Has anyone tried pairing it with their phone? How is call volume both ways? Can you adjust the volume so you can easily hear it over highway noise?
Can you transfer your contacts?
Can you make outgoing calls by voice commands?
The car is very quiet, so you should not have a problem with hearing or someone hearing you.
As far as connectivity, that depends on the phone and the carrier. For example, Verizon does not support phonebook transfers. The latest PDA's use a higher version of firmware so tend to not work well.
The voice command takes a learning curve I have noticed.